Electrical transmission system conductor installation technique

ABSTRACT

A typical embodiment of the invention is directed to a &#34;Horizontal Vee&#34; power transmission line conductor installation system. Typically, a connector protrudes from the insulator coupling. A cable clamp is releasably attached to the connector. An auxiliary cable seized in the clamp also is attached through cable grips to the line conductor. A come along transfers load from the line conductor to the cable to enable the slackened portion of the line conductor to be clipped by a suspension clamp and permanently joined to the connector. The auxiliary cable is released from the line conductor and removed from the connector in order to transfer the line conductor load back to the line conductor. This technique avoids the need for cranes, jib poles and other erection equipment and also avoids imposing excessive forces on the electrical insulators during installation.

This is a division, of application Ser. No. 139,048, filed Apr. 10, 1980now U.S. Pat. No. 4,312,495.

BACKGROUND OF THE INVENTION

This invention relates to methods and apparatus for temporarilysupporting high voltage electrical transmission conductors duringtransmission system installation and, more particularly, to methods andapparatus for temporarily supporting high voltage electrical conductorswhile they are being clipped to high voltage insulator assemblies on apower transmission pole by means of an auxiliary cable and conductorclipping aid, and the like.

For a number of reasons, of which cost and environmental considerationsare perhaps paramount, electrical utility companies have been strivingto reduce the width of the right-of-way that is required to transmitelectrical power. There also is a further need to improve the physicaland aesthetic appearance of electrical power transmission systems.

Toward satisfying these ends, the "Horizontal Vee" electricaltransmission system that is described in U.S. Pat. No. 3,002,043 grantedSept. 26, 1961 to R. I. Jenner et al. for "Electrical TransmissionSystem" has been quite successful. As described in the Jenner et al.patent, a suspension insulator is connected to an electricaltransmission system pole in a manner that enables the suspensioninsulator to extend from the pole in a downward and outward direction.The downwardly and outwardly protruding end of the suspension insulatoris joined to one end of a horizontal strut insulator, the opposite endof the strut insulator being connected directly to the powertransmission system pole. The combined suspension and strut insulatorsform the "Horizontal Vee" and it is the junction of the two insulatorsthat form this vee to which the line conductor is attached.

Although this "Horizontal Vee" installation has been widely accepted andvery successful in reducing right-of-way width requirements for a givenpower rating, there is, nevertheless, a further need to simplify lineconductor insulation procedures in order to reduce over-all systeminstallation costs.

Typically, a crane or jib pole temporarily supports the line conductorwhile the conductor is being permanently clamped to the "Horizontal Vee"insulators on the transmission pole. This use of jib poles or cranes totemporarily lift and hold the conductor is expensive in terms ofpersonnel and equipment, as well as being a tedious and time-consumingprocess. This technique, moreover, has the further disadvantage ofimposing abnormal loads during installation on the pole structure.Clearly, there is a need for improved methods and apparatus for mountingline conductors to "Horizontal Vee" power transmission systems.

BRIEF SUMMARY OF THE INVENTION

Illustratively, a clevis and sheave combination is suspended from aconnector or support rod that protrudes downwardly from the junctionbetween the suspension and strut insulators on a transmission systempole. The line conductor is drawn through the clevis to bear upon and betangent to the grooved upper surface of the sheave. Cable grips areattached to the line conductor on opposite sides of the sheave to enablean auxiliary cable or wire rope to pass through the aperture in aclipping aid clamp which is attached to the connector. A "come-along,"which also is attached to the wire rope, is manipulated to tighten theauxiliary cable and produce some slack in the portion of the lineconductor that is seized between the cable grips.

With sufficient slack provided, the clevis and sheave combination isdismounted from the connector to permit a suspension clamp to beattached to the line conductor at the same point as the point oftangency between line conductor and the groove in the sheave. Thesuspension clamp on the slack portion of the line conductor then isattached to the connector which protrudes downwardly from the junctionbetween the two insulators. The come-along is removed and the wire ropewith its associated cable grips also is removed, transferring the lineconductor load directly to the "Horizontal Vee" assembly.

A further salient feature of the invention is the temporary addition ofa clamp or clipping aid to the connector. This clipping aid accommodatesthe auxiliary cable, the cable grips and the come-along.

These and other features of the invention are shown in more completedetail in the following description of a preferred embodiment of theinvention when taken in conjunction with the drawing. The scope of theinvention, however, is limited only by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation of a typical assembly for mounting a lineconductor to a transmission system insulator assembly in accordance withthe principles of the invention; and

FIGS. 2 through 6 are side elevations of a sequence of steps forpracticing a preferred embodiment of the invention in connection withthe device that is shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

For a more detailed understanding of the invention, attention is invitedto FIG. 1 which shows a bracket 10 that has a base 11 in which fourapertures 12 and 13 are formed to accommodate the shanks of bolts (notshown in FIG. 1). These bolts attach the bracket 10 to a strut insulator(also not shown in FIG. 1) of a "Horizontal Vee" high voltage insulatorassembly. The bracket 10 protrudes from the base 11 and terminates in abifurcated end 14 which forms a clevis that accommodates a connector 15.

As shown in FIG. 1, one end of the connector 15 has an eye 16 that ispinned within the bifurcated end 14 of the bracket 10. The shank of theconnector 15 protrudes in a downward direction from the bifurcated end14 of the bracket 10. The lowermost end of the connector 15 terminatesin an end that is finished with ball joint 17. A flange 20, moreover, isformed on the shank of the connector 15 about one quarter of thedistance from the ball joint 17 toward the eye 16.

The shank of the connector 15 also is provided with an aperture 21 thatis near the eye 16 of the connector, but spaced slightly below thebracket 10. The aperture 21 accommodates a bolt 22 that temporarilyjoins an "L" shaped two-component assembly comprised of members 23 and28 to the connector 15.

In accordance with a salient feature of the invention, member 28 has anupright and vertically oriented leg 24 and is provided with apertures 25and 26. The aperture 25 is in axial alignment with the aperture 21 inthe connector 15 in order to accommodate the shank of the bolt 22. Thusbolt 22 and nut 27 fasten the assembly temporarily to the connector 15.Member 28 has a base 30 which is flat on the lower side that is adjacentto the ball joint 17 and has a groove 31 on the upper side that isoriented toward the bolt 22.

A cable or wire rope 32, which will be described subsequently in morecomplete detail, is lodged in the groove 31. Note, moreover, that theends of the groove 31 are provided with a chamfer 33. A keeper member 23is attached to the aperture 26 in member 28 by means of a bolt 35, orthe like, in the vertical leg 34. The keeper 23 also has a general "L"shape that nests within the crook formed by the vertical leg 24 and thebase 30 of member 28.

As illustrated, the horizontal leg 36 of the keeper 23 also is providedwith a chamfered groove 37 that is opposite to and in alignment with thegroove 31 in member 28. In this way, member 28 and the keeper 23 clampthe wire rope 32 to the connector 15 and the bracket 10. This clampingdoes not prevent relative movement in an axial direction between thecable 32 and the combined keeper 23 and member 28 as well as the shank15. It should also be noted that the keeper 23 and member 28 combinationform a clipping aid that can be removed from the connector 15 and thebracket 10 as described subsequently in more complete detail.

Attention now is invited to FIG. 2, which shows member 28 and the keeper23 attached to the connector 15, which is mounted by means of thebracket 10 and the base 11 at the juncture between a suspensioninsulator 40 and a strut insulator that is directly behind the base 11of the bracket 10. The extremities of the wire rope 32 are provided withcable grips 41 and 42 which temporarily clamp the wire rope to a lineconductor 43. A come-along 44 also is accommodated on the wire rope 32between the assembly of keeper 23 and member 28 and the cable grip 41,also as shown in FIG. 1.

A clevis 45 is connected to the ball joint (not shown in FIG. 2) at thedownwardly depending extremity of the connector 15 in order to support arotatable sheave 46. The sheave 46 is provided with an annular groove 47to which the line conductor 43 is tangent. The line conductor 43,moreover, is marked at its midpoint between the cable grips 41 and 42 atthat point of tangency with the groove 47 in the sheave 46.

Turning now to FIG. 3, it can be seen that the come-along 44 has beenmanipulated to enable the tension in the line conductor 43 to be takenup by the wire rope 32 and permit the section of the line conductor 43that is clamped between the cable grips 41 and 42 to hang slack oneither side of the sheave 46. The sheave 46 and the clevis 45 areremoved from the connector 15 to enable the portion of the lineconductor 45, between the cable grips 41 and 42, to hang in an arcuatebow.

As shown in FIG. 4, the portion of the line conductor 43 that is seizedbetween the cable grips 41 and 42 may be wrapped with a serving of armorrods 50 in the vicinity of the marked tangency point. A suspension clamp51 is attached to the whipped portion of the line conductor 43. As shownin the drawing, the suspension clamp 51 has a groove base 52 in whichthe whipping and the immediately adjacent portion of the line conductor43 are secured by means of a pair of inverted U bolts 53 and 54. Thesuspension clamp also is provided with an apertured clevis 55 which iscoupled to a fitting 56. The head of the fitting 56 which protrudesabout the apertured clevis 55 of the suspension clamp is provided with asocket (not shown in the drawing) that can be fastened to the ball joint17 on the end of the connector 15.

Thus, as illustrated in FIG. 5, the ball joint 17 (FIGS. 1, 2, 3 and 4)of the connector 15 is fitted into the mating socket within the fitting56 to join the suspension clamp 51 and the portion of the line conductor43 that is seized by the clamp 51 to the assembly for the "HorizontalVee" installation. Note that following the joining of 17 and 56, thecome-along 44 that is shown in FIGS. 2,3 and 4 can be removed from thewire rope 32. The cable grips 41 and 42 are released from the lineconductor 43 to enable the clamp 51, the fitting 56 and the connector 15with its associated bracket 10 to bear the full load of the associatedportion of the line 43. Thus, FIG. 6 shows a completed line conductorinstallation in which the conductor 43 and its whipped portion that isseized within the suspension clamp 51 is sustained by the connector 15,the bracket 10 and the "Horizontal Vee" assembly 57 which, in turn,transfers the entire load to the pole 60.

Turning once more to FIG. 1, it should be noted that the cable 32 isremoved from the connector 15 by unthreading the bolt 22 from the nut 27to release the clipping aid combination of member 28 and keeper 23 fromthe connector 15.

Although the invention has been described in conjunction with a"Horizontal Vee" installation, it can also be used effectively where aconductor is suspended from a vertical string of suspension insulatorsor a cantilevered post insulator. These constructions are well known inthe art. Additionally, the clipping aid has been shown composed of twocomponents, both attached to the connector. Where desirable, thesupporting component 24 could be an integral part of connector 15.

Consequently, there is provided in accordance with the invention, amethod and apparatus for securing line conductors to electrical highvoltage insulator assemblies without the use of jib poles, cranes orother costly construction equipment. This not only reduces constructioncosts, but also avoids imposing extraordinaly loads on the "HorizontalVee" assembly during the line conductor installation.

I claim:
 1. In a power transmission system comprising a pole forsupporting a line conductor, a suspension insulator having a first endconnected with the pole and a second end extending from said pole in adownward and outward direction, and a strut insulator extending fromsaid pole to form a junction with the suspension insulator at the secondend thereof, the improvement being a conductor erection systemcomprising:a bracket mounted to said junction of said insulators; aconnector suspended from said bracket, said connector having an upperend and a lower end; a cable clamp detachably secured to said connectornear said upper end thereof, said cable clamp having an aperturedisposed with its axis parallel to the direction of said conductor andthrough which aperture a cable can be slid; a cable secured by saidcable clamp, both ends of said cable being attached to the lineconductor, said cable being slidably disposed within said cable clampfor raising said conductor; means for transferring load from the lineconductor to said cable, said transferring means including a sheaveassembly detachably securable to the lower end of said connector fortemporary support of said conductor; and a conductor clamp securable tosaid line conductor for attachment of the line conductor to the lowerend of said connector.
 2. A clipping aid for a power transmission systemincluding an electrical insulator for support of a line conductor, saidclipping aid comprising a bracket attached to said electrical insulator,a connector having an upper end and a lower end and being suspended byits upper end from said bracket, a conductor clamp, said connectorhaving means for attachment of said conductor clamp for sustaining aline conductor, said clipping aid further comprising means including acable for temporarily supporting the line conductor, said supportingmeans being releasably attached to said connector near said upper endindependently of said attachment of said conductor clamp, said clampattachment means being located at the lower end of said connector forsecuring said conductor clamp to the lower end of said connector, saidtemporary supporting means including a cable clamp detachably securableto said connector near its upper end and having an aperture thereinthrough which said cable can be slid in a direction parallel to saidconductor for raising said conductor, whereby the weight of saidconductor can be transferred from said temporary supporting means tosaid conductor clamp.
 3. A clipping aid according to claim 2 whereinsaid bracket comprises an outer end bifurcated to form a clevis, saidclamp attachment means being formed at the bottom end of said connectorand having a base at said bottom end for attachment to said lineconductor via said conductor clamp.
 4. A clipping aid according to claim3 wherein said supporting means further comprises a body for temporaryattachment to said connector, and a keeper attached to said body forengaging a cable therebetween, said keeper having an arcuate rim forforming part of said aperture for the slidable support of said cable.